Perhaps you should try some spelling variations:
thu hang » thi hang, thuc hanh, thu huong
phat duc » pham duc, phan duc, phan duoc
tu sach » thu sach, su sach, te sach
tu hang » tu hanh, tu hung, ty hang
hieu va » lieu va, hieu qua
va tinh » may tinh
hai cua » thai cua, dai cua, lai cua
hoi cua » hoi chuc

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ((tu hang) or (thu hang)) xa hoi. hieu va phat duc va tinh ((hai cua) OR (hoi cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((tu hang) OR (thu hang)) xa hoi. hieu va phat duc va tinh ((hai cua) OR (hoi cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((tu hang) or (thu hang)) xa hoi. hieu va phat duc va tinh ((hai cua) OR (hoi cua)) tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ((tu hang) or (thu hang)) xa hoi. hieu va phat duc va tinh ((hai cua) OR (hoi cua)) tre*.